Answer: Inflammatory tinea capitis. The differential diagnosis included acute bacterial abscesses, tinea capitis (kerion), seborrheic dermatitis, atopic dermatitis, alopecia folliculitis, and psoriasis. Upon presentation, the patient was diagnosed with kerion, the most exaggerated cellular response to tinea capitis, a fungal infection of the scalp and hair shaft (1, 2). A patient's history and physical examination results are often used to make a clinical diagnosis; however, clinical diagnosis is often unreliable, making laboratory confirmation necessary (3, 4). Specimens should be aspirated for a superior sample or collected via the toothbrush or cotton swab method, which involves rubbing the respective sterile object over the lesions and sending it to the laboratory for evaluation (5, 6). Microscopic evaluation using 10 to 20% potassium hydroxide, with or without a fungal stain, such as calcofluor white for enhancement of hyphal elements, should be performed (3). Additionally, cultures should be sent, due to the potential for false negatives with the use of potassium hydroxide smears in patients with early or inflammatory tinea capitis (2). Specimens should be plated on one medium containing cycloheximide, such as dermatophyte test medium, and one medium without cycloheximide. Dermatophyte test medium changes from yellow to red in the presence of dermatophytes, including Microsporum canis and Trichophyton tonsurans, the pathogens most often implicated in tinea capitis. Confirmatory cultures may require a 3- to 4-week incubation period, and treatment should be initiated immediately for all patients for whom there is a high level of suspicion. Treatment requires systemic therapy, due to inadequate absorption of topical therapeutic agents into the hair shaft (1, 4). Currently, griseofulvin at 20 to 25 mg/kg of body weight/day is considered the gold standard treatment for tinea capitis, although treatment with newer agents such as itraconazole and terbinafine may be as effective (2). Mycological cure rates for a 6- to 8-week treatment course range from 70 to 100%, depending on dose, duration, and causative organism. Adjunctive therapeutic agents, such as 2% ketoconazole or 1% selenium sulfide shampoo, are effective at reducing the risk of transmission once oral therapy has been initiated by reducing the keratin food source for the fungus. Initial stains demonstrated hyphae, and cultures subsequently grew out Trichophyton tonsurans. The patient had been empirically started on griseofulvin at 500 mg daily with dinner and 1% selenium sulfide shampoo nightly and was to return to clinic in 4 weeks for a follow-up. (See page 1027 in this issue [doi:10.1128/JCM.00020-13] for photo quiz case presentation.)